In a principal aspect, the present invention relates to an improved method for batch drying grain and the like.
Previously, in U.S. Pat. No. 2,826,824, Drying Method, issued Mar. 18, 1958, a method for batch drying grain is disclosed. In general, a plurality of separate bins are filled with grain for drying. A series of doors in the upper and lower sides of the bins are connected with manifolds or common ducts. Doors are also arranged to interconnect the manifolds. By appropriately opening and closing various doors, it is possible to cycle the air supplied to the bins in a sequential manner. After the air is cycled as desired, it exhausts through a trap door in the top of a bin. Various arrangements of doors are employed to permit filling and removal of grain from the separate bins as other bins of grain are being dried.
During particularly cold weather, the exhausted air is sufficiently above ambient temperature that great amounts of energy are lost from the drying system. Also, the heat of vaporization of the moisture evaporated from the product is lost. This decreases the efficiency of the grain drying operation, since cold ambient air must be heated in order to maintain a continuous supply of dry, heated air for simultaneously drying the separate batches of grain. The capacity of the drying system is also reduced when the weather is particularly warm and humid. Such disadvantages are the type which the subject matter of the present invention seeks to overcome.